Self-locking box



Dec. 18, 1951 P, o. THEANDER 2,579,346

' SELF-LOCKING BOX Filed April 29, 1948 2 SHEETS-SFEET 1 PLR OLAF THEANDEF? ATT RNEYS Dec. 18, 1951 'P. o. THEANDER 2,579,346

SELF-LOCKING BOX Filed April29, 1948 2 SI-IEETS-Sl-1E ET 2 awe/MM PER OLAF, THUNDER ATTORNEYS Patentecl Dec. 18, 1951 SELF-LOCKING BOX I Per 0101? Theander, Goteborg, Sweden Application April 29, 1948, Serial No. 23,990

In Sweden September 26, 1945 2 Claims.

The present invention relates to cardboard boxes of the kind comprising a receptacle with a. rectangular bottom portion and ,four .walls perpendicular to said bottom portion, and a cover having a rectangular top portion and four walls perpendicular to said central portion, the receptacle and the cover, respectively, formed from a single blank by folding the blank portions projecting from opposite edges of the bottom portion and the top portion, respectively, each of said projecting portion of the blank being by two creasing lines parallel to said edges divided into three sections, whereby the sections adjacent the bottom portion and the top portion, respectively, are erected to form right angle to said bottom portion and said top portion, respectively, the sections situated outside the last mentioned sections are folded downwardly along the inner'side of said sections, and the outermost sections are folded inwardly along the bottom portion of the receptacle and the top portion of the cover, respectively. More particularly, the invention relates to boxes of the kind referred to, in which the walls of the receptacle are' provided with a number of slots parallel to the bottom portion -of the receptacle, and in which the side walls of the cover are provided with slots, which are parallel to the top portion of the cover and so positioned that,

when the cover is placed in position on the receptacle they will register with the slots provided in the walls of the receptacle, whereby the wall portions are along the one side of each slot bent out of the plane of the respective wall in such a manner that, when placing the cover in position, the portions of the wall of the cover thus bent outwardly will snap over the corre sponding portions of the Walls of the receptacle thus locking the cover in its position on the receptacle.

The general object of the invention is to improve and simplify boxes of the kind referred to, so as to render them reliable in use, inexpensive to manufacture, and easy to manipulate.

The invention is broadly characterized in that the slots of the receptacle are provided in the blank sections adjacent the bottom portion in the vicinity of the creasing lines between said sections and the sections bent downwardly along the inner side of the same, so that the strain or stresses occurring in the cardboard when folding down the last-mentioned sections will bend the cardboard portions situated between the slots and said creasing lines out of the plane of the respective wall.

being partly in section along the line V--V in Figure 6, and Y Figure 6 is a transverse sectional view of the box along the line VI-VI in Figure 5.

Referring-first to Figures 1-4, ldenotes the rectangular bottom portion of an open receptacleformed from a single blank of cardboard and provided with four walls forming right angles? to the bottom portion. Two of said walls.op-- posite each other are formed'from cardboard portions projecting from the longitudinal edges' of the bottom portion; each of said projecting portions being by twocreasing lines 2 and 3 pare" allel to said edges divided into three rectangular.

sections 4, 5 and 6', respectively. The'sectionsiil' adjacent the bottom portion l are erected per-" pendicularl to thebottorn portion I, the'seci-"- tions 5 outside the'se'ctions 4 are folded downj-' wardly along the inner side of the sections 4, and the outermost sections 6 are foldedinwardly' along the inner side of the bottom portion I. The cover which in the same manner is formed from a single cardboard blank consists of a rectangular top portion I end four walls forming right angles to the top portion. Two of said walls opposite each other are formed from cardboard portions projecting from the longitudinal edges of the top portion l, and each of said projecting portions are by two creasing lines 8, 9 divided into three rectangular sections l0, H and I 2, respectively. The sections In adjacent the top portion 1 are erected perpendicularly to the top portion 1, the sections ll outside the sections II are folded downwardly along the inner side of the sections it, and the outermost sections l2 are folded inwardly along the inner side of the top portion l. The cover is sized to telescope over the receptacle when placing it in closed position. According to the invention each of the sections 4 of the side walls of the receptacle is provided with two slots l3 parallel to the creasing line 3. On account of strains or stresses occurring in the cardboard when folding down the sections 5 along the sections 4 the portions l4 of the sections 4 situated between the slots or incisions l3 and the creasing lines 3 will be bent out of the plane of the sections 4, as clearly appears from Figure 4. The sections ll of the side walls of the cover are in the same manner provided with slots or incisions 15 parallel to the creasing lines 8 and so positioned that when the cover is placed in position the slots [5 will register with the slots l3. Owing to stresses or'zstrains occurring: in the cardboard when "folding the section's I! along the sections Hi the cardboard portions l6 situated at the one side of the slots l5 will be bent out of the plane of the sections H as clearly appears from Figure 4. When placing the cover on the receptacle the cardboard 'p'ortionsliianii l6 thus bent out will snap overweach otherand automatically lock the cover in closed positiont When the cover is to be removed one of the side walls of the receptacle which is accessible" through a recess I! at the edge of the correspending wall 'of the cover is pushed I inwardly by means of a finger, whereby"the cardboard portions M and fli arebrought out ofenga'gement with each other so that-' the-:c'over' ma be removed.

The embodiment-shown in Figures arrdfd differs from the embodiment-described above-only by the fact, that the slots or"incisions13in the wallfsection' l'ofithe receptacle are curvecl at" their ends so asto reach the creasing lines- '3; In the sa'me man'nerthe slots or incisiensin the wall section ll of the cover are curved at their ends-so as -toreachthe-ereasihg lines ii. Y I

-' 1. Improvements in'cardboard boxes' comprising in combination a=container -forme'cl' from a single sheet of folded material, said container having a pair of opposite walis -eaoh formed by two parallel sections- Tolded-togetherand along an common line :of said'tmaterial, the outside "sec;- tion 01'? :each: for said ppposite walls having longitudinal I'slits formed in "the: imedial' "portions thereof with earhislitiforming Ya bulge :extending in .its .respective tsectibn between said common ioldalinepf the sectionzarrdisaidfslit and ax'eover forsaid-icontainer formedsalsoiromaasinglesheet of: .:folded material, :said cover "having a: 1 pair of opposite walls eaclrformed: by two parallel sections .folded together andsalong a' common. line of "said material, the insidevsection of: each of 4 said opposite walls having longitudinal slits for-med in the medial portions thereof with each slit forming a bulge extending in its respective section between said common fold line of the section and said slit and said slits of said cover being positioned for aligning with said slits of said container when said cover is on said container.

2. Improvements in :cardboarifiboiws comprisingin "combination a container "formed from a single sheet of material having rectangular secti'ons folded around a central portion forming the base, for providing a pair of opposite side walls and end walls extending therebetween, said sidewalls eaehbeing formed by parallel sections rtolded together and along a line forming a top sidewall having longitudinal slits formed in the medial portions thereof with each slit forming a bulge extending in its respective section between the top iedgexcf saidwallzandxsaid slit-iand a co'ver for isaid :container formedzfrom :a single sheet of material having rectangular sections folded around a central portion forming the top :ofi said coverior providing .a pair of :iopposite side wallsand end walls extending therebetween, said cover sidewalls each beingformedr by parallel se'ctionsrfolded together andsalong a line'forming the o'penflend of said-cover;xthe innerssection=of each cover side wall having longitudinal. slits formed'i'n the medial? portionsvtheredf with; each slit forming a bulge extendinglinirits respective section between therop'ezrend of. said cover and.

said slit and said slits of saidlcov'er' being13posi= tioned for: aligningwitlnsaidxslitsroi said container when said cover is in place vonsaid acontainer; PER 013013" IHEANDER.

REFER-ENGES- CELEB The following references are of record in'the fil'eo'fthis patent:

UNITED STATES LPATENI'S Number Name Date- 651,070 Enoch June 5,1900- l,j6.46,665 Smith t v. Get. 25-, 1927 2,122,904 Ambrosius' July .5, :1938 2,189,602. Denny Feb; 6, 1949 2,373,977 'Scherer a .-Apr. 17,1945 2,412,402 Huyea -Dec. 10', 1946 

